Cross schema joins with typeorm - postgresql

Question

Steps to reproduce:
Create 2 schema a and b
Create tables user, photo in both schema with these respective entities UserA PhotoA, UserB PhotoB
// PhotoA
import {Entity, Column, PrimaryGeneratedColumn, ManyToOne} from "typeorm";
import { User as UserB } from "./User.b";
import { User as UserA } from "./User.a";
#Entity({schema: "a"})
export class Photo {
#PrimaryGeneratedColumn()
id: number;
#Column({
length: 100
})
name: string;
#ManyToOne(type => UserA)
userA: UserA;
#ManyToOne(type => UserB)
userB: UserB;
}
// UserB
import {Entity, Column, PrimaryGeneratedColumn, OneToMany} from "typeorm";
import { Photo as PhotoA } from "./Photo.a";
import { Photo as PhotoB } from "./Photo.b";
#Entity({schema: "b"})
export class User {
#PrimaryGeneratedColumn()
id: number;
#Column({
length: 100
})
name: string;
#OneToMany(type => PhotoA, photo => photo.userB)
photosA: PhotoA[]
#OneToMany(type => PhotoB, photo => photo.userB)
photosB: PhotoB[]
}
Run this code
import "reflect-metadata";
import * as typeorm from "typeorm";
import { Photo as PhotoA } from "./entities/Photo.a";
import { User as UserB } from "./entities/User.b";
import { PostgresConnectionOptions } from "typeorm/driver/postgres/PostgresConnectionOptions";
import { Photo as PhotoB } from "./entities/Photo.b";
import { User as UserA } from "./entities/User.a";
class Inl {
public async test() {
const connection = await typeorm.createConnection({
type: "postgres",
host: "localhost",
port: 5433,
username: "test",
password: "test",
database: "test",
synchronize: true,
logging: true,
entities: [ PhotoA, PhotoB, UserA, UserB ]
} as PostgresConnectionOptions);
const photoARepo = connection.getRepository(PhotoA);
const userBRepo = connection.getRepository(UserB);
const userBRow = new UserB();
userBRow.name = "User in schema B";
const userBSavedRow = await userBRepo.save(userBRow);
const photoARow = new PhotoA();
photoARow.name = "Photo in schema A";
photoARow.userB = userBSavedRow;
await photoARepo.save(photoARow);
const photoBRow = new PhotoB();
photoBRow.name = "Photo in schema B";
photoBRow.userB = userBSavedRow;
await photoARepo.save(photoARow);
const result = await userBRepo
.createQueryBuilder("userB")
.select("*")
.leftJoinAndSelect("a.photo", "photosA")
.leftJoinAndSelect("b.photo", "photosB")
.where({id: userBSavedRow.id})
.getOne();
console.log(result);
}
}
new Inl().test();
RESULTS
query: INSERT INTO "a"."photo"("name", "userAId", "userBId") VALUES ($1, DEFAULT, $2) RETURNING "id" -- PARAMETERS: ["Photo in schema A",6]
query: COMMIT
query: SELECT "Photo"."id" AS "Photo_id", "Photo"."name" AS "Photo_name", "Photo"."userAId" AS "Photo_userAId", "Photo"."userBId" AS "Photo_userBId" FROM "a"."photo" "Photo" WHERE "Photo"."id" IN ($1) -- PARAMETERS: [6]
(node:527) UnhandledPromiseRejectionWarning: Error: "a" alias was not found. Maybe you forgot to join it?
at QueryExpressionMap.findAliasByName (/home/lewis/Projects/internationalisation/src/query-builder/QueryExpressionMap.ts:341:19)
at JoinAttribute.getValue (/home/lewis/Projects/internationalisation/src/query-builder/JoinAttribute.ts:146:72)
at JoinAttribute.get [as relation] (/home/lewis/Projects/internationalisation/src/query-builder/JoinAttribute.ts:162:53)
at JoinAttribute.get [as metadata] (/home/lewis/Projects/internationalisation/src/query-builder/JoinAttribute.ts:175:18)
at SelectQueryBuilder.join (/home/lewis/Projects/internationalisation/src/query-builder/SelectQueryBuilder.ts:1299:27)
at SelectQueryBuilder.leftJoin (/home/lewis/Projects/internationalisation/src/query-builder/SelectQueryBuilder.ts:284:14)
at SelectQueryBuilder.leftJoinAndSelect (/home/lewis/Projects/internationalisation/src/query-builder/SelectQueryBuilder.ts:364:14)
at Inl.test (/home/lewis/Projects/internationalisation/index.ts:42:14)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:160:7)
As you can see from the log, I'm having the error alias was not found with the above code. Anybody has hints on this?

Answer 1

The problem here is that your are mixing up schema and alias in leftJoinAndSelect (the schema is resolved by TypeOrm, you don't need to specify this in your query if your entity is correctly configured). So this should work:
const result = await userBRepo
.createQueryBuilder("userB")
.leftJoinAndSelect("userB.photosA", "photosA")
.leftJoinAndSelect("userB.photosB", "photosB")
.where({id: userBSavedRow.id})
.getOne();